In a typical electrostatographic reproducing apparatus, a light image of an original to be copied is recorded in the form of an electrostatic latent image upon a photosensitive member and the latent image is subsequently rendered visible by the application of toner. The visible toner image is then in a loose powdered form and can be easily disturbed or destroyed. The toner image is usually fixed or fused upon a support which may be the photosensitive member itself or other support sheet such as plain paper.
The use of thermal energy for fixing toner images onto a support member is well known. To fuse toner onto a support surface permanently by heat, it is usually necessary to elevate the temperature of the toner to a point at which the constituents of the toner coalesce and become tacky. This heating causes the toner to flow to some extent into the fibers or pores of the support member. Thereafter, as the toner cools, solidification of the toner causes it to be firmly bonded to the support.
In color fusing, customer preference for color prints is often a high gloss or matte opaque finish. This usually requires the use of a smooth, conformable heat member operating at a high temperature and having a long-dwell nip. In addition, extra release agent is necessary for improving toner release due to the increase in toner used for color developing. For developing color images, several layers of different color toner are deposited on the latent image resulting in extra thickness (higher toner pile height) of unfused toner on a color image. Therefore, a higher operating temperature for color fusers is necessary. Further, extended dwell time at the nip is necessary to ensure complete toner flow. In addition, a conformable fusing member is necessary in order to ensure sufficient release and stripping. Moreover, a smooth surface is necessary in order to provide color images with preferred increased gloss.
However, known fusing members do not provide the quality for colored images as they do for black and white images. Therefore, it is desired to provide a heat member, preferably in combination with a pressure member, wherein high quality color prints or copies are produced. Particularly, it is desired to provide fusing members demonstrating excellent results at the higher temperatures necessary in color fusing. In addition, it is desired to provide fusing members which require little or no fusing oil on the outer surface, while still providing excellent release. Further, it is desired to provide fusing members which provide complete toner flow, and increased gloss. Moreover, it is desired to reduce or eliminate pinhole defects in the polymeric layer of the fusing member.